Pfizer vaccine shows 100 per cent efficacy in 12-15 year olds: US study
For the study, 2,260 adolescents participated aged between 12 to 15 years, of which 1,131 were given the vaccine (BNT162b2) and 1,129 were given a placebo.

For the study, 2,260 adolescents participated aged between 12 to 15 years, of which 1,131 were given the vaccine (BNT162b2) and 1,129 were given a placebo.
Developed by Bharat Biotech in partnership with National Institute of Virology and the Indian Council of Medical Research, Covaxin was approved for emergency use on January 3. Trial results later showed the vaccine has an efficacy of 78 per cent.
Authorities have to "consider ways to solve the issue that efficacy rates of existing vaccines are not high", Chinese media outlet The Paper reported, citing Gao Fu, the head of the Center for Disease Control and Prevention.